1. Field of the Invention
The present invention relates to an optical coherence tomographic imaging apparatus for capturing a tomographic image of a subject's eye through optical coherence, and a method for controlling the optical coherence tomographic imaging apparatus.
2. Description of the Related Art
A presently known optical coherence tomographic imaging apparatus based on optical coherence tomography (OCT) utilizes multi-wavelength light wave interference. For example, the optical coherence tomographic imaging apparatus is used to acquire internal organ information with an endoscope and retina information in an ophthalmologic apparatus, and applied to increasing number of fields in the human body. An optical coherence tomographic imaging apparatus applied to the human eye is becoming essential for specialized retina clinic, as an ophthalmologic apparatus.
Such an optical coherence tomographic imaging apparatus is capable of irradiating a sample with measuring light which is low-coherent light, and measuring backward scattering light from the sample by using an interferometer. In a case one point on the sample is irradiated with the measuring light, image information in a depth direction at the one point on the sample can be acquired. Further, by performing measurement while scanning the sample with the measuring light, a tomographic image of the sample can be acquired. In a case the optical coherence tomographic imaging apparatus is applied to the fundus, the fundus of the subject's eye is scanned with the measuring light to capture a high-resolution tomographic image of the fundus of the subject's eye. Therefore, the optical coherence tomographic imaging apparatus is widely used in ophthalmology diagnosis of the retina.
Generally, the optical coherence tomographic imaging apparatus uses a method for capturing a plurality of tomographic images by repetitively scanning a measurement target (fundus), in a horizontal or vertical direction. Thus, the optical coherence tomographic imaging apparatus scans an identical region on the fundus a plurality of times to capture a plurality of tomographic images of the identical region, and performs averaging processing on the captured tomographic images to acquire a high-definition tomographic image of the fundus. Further, by scanning the fundus a plurality of times while moving the scanning position in parallel, a three-dimensional image of the fundus can be acquired. In a case scanning the fundus a plurality of times in this way, however, since it takes a certain amount of time to complete image capturing, the eye may move during image capturing.
Japanese Patent Application Laid-Open No. 2008-29467 discusses an ophthalmologic imaging apparatus having a tracking function. Specifically, the ophthalmologic imaging apparatus successively captures a plurality of front images of the subject's eye, detects the subject's eye movement by using the plurality of acquired front images, and corrects scanning positions according to the subject's eye movement.